Emphasis on soil conservation in recent times has been brought about by the degradation of soils due to intensive tillage operations. A relatively new tillage philosophy, coined conservation tillage, has opened up a new realm of tillage equipment design. The Rotary Tine Aerator (RTA) is new tillage tool that is starting to see commercial applications within the agriculture industry.<p> Being a new tillage tool, very little information has been gathered about the RTA and especially the variables that affect tool loading. For the purpose of improving the design of the soil engaging components of the RTA, an experiment was carried out investigating the effect various settings have on tool loading. A factorial experiment was set up with three factors and two levels. The variables examined were depth, velocity of the tool carriage and tine, and the tine gang angle, with soil density and moisture content maintained constant.<p> Draft and vertical forces on the frame were seen to increase with depth. Side loading on the bearing mounts was seen to be primarily affected by the angle of the tine gang, increasing as the gang angle increased. Tool shape was seen to affect the side loading of the bearing mounts causing the force to change directions when the tool was working and 20 cm depth and the tine gang was set a 0º. Forward velocity was not seen to be a significant factor affecting forces on the frame.<p> The loading in the X, Y and Z direction on the tine increased as depth increased from 10cm to 20 cm. A decrease in force on the tine in the X, Y and Z direction was seen with increasing tine velocity. It is suggested that an overlap in soil failure zones could be the cause of this relationship. Opening the gang angle from 0º to 10º increased the force in the Z direction and decreased the force in the X direction. Tool shape was also seen to affect the direction of the load on the tine in the Z direction when the tine was tilling at a depth 20cm with a tine gang of 0º.<p> From the information gathered in this experiment, statistical models were developed for the loading on the tine and frame. The all possible regressors approach was used to formulate the statistical models. As each regressor was added, the new equations fit was assessed using the coefficient of determination (R2 ) and the sum of squared error (SSE). If there was a discrepancy as to whether an added regressor significantly contributed to the fit of the equation, a hypothesis test using the F-statistic was used to justify the regressors addition or removal. The models were then compared against the original data.<p> The models developed for the tine loading showed sufficient accuracy. The models for side loading of the bearing mounts and draft loading of the tool frame contained only one significant regressor. The lowest coefficient of correlation was R=0.63 for the model of side loading of the bearing mount. The statistical model for the vertical loading correlated well with the test data with a coefficient of correlation of R=0.95.

Emphasis on soil conservation in recent times has been brought about by the degradation of soils due to intensive tillage operations. A relatively new tillage philosophy, coined conservation tillage, has opened up a new realm of tillage equipment design. The Rotary Tine Aerator (RTA) is new tillage tool that is starting to see commercial applications within the agriculture industry.<p> Being a new tillage tool, very little information has been gathered about the RTA and especially the variables that affect tool loading. For the purpose of improving the design of the soil engaging components of the RTA, an experiment was carried out investigating the effect various settings have on tool loading. A factorial experiment was set up with three factors and two levels. The variables examined were depth, velocity of the tool carriage and tine, and the tine gang angle, with soil density and moisture content maintained constant.<p> Draft and vertical forces on the frame were seen to increase with depth. Side loading on the bearing mounts was seen to be primarily affected by the angle of the tine gang, increasing as the gang angle increased. Tool shape was seen to affect the side loading of the bearing mounts causing the force to change directions when the tool was working and 20 cm depth and the tine gang was set a 0º. Forward velocity was not seen to be a significant factor affecting forces on the frame.<p> The loading in the X, Y and Z direction on the tine increased as depth increased from 10cm to 20 cm. A decrease in force on the tine in the X, Y and Z direction was seen with increasing tine velocity. It is suggested that an overlap in soil failure zones could be the cause of this relationship. Opening the gang angle from 0º to 10º increased the force in the Z direction and decreased the force in the X direction. Tool shape was also seen to affect the direction of the load on the tine in the Z direction when the tine was tilling at a depth 20cm with a tine gang of 0º.<p> From the information gathered in this experiment, statistical models were developed for the loading on the tine and frame. The all possible regressors approach was used to formulate the statistical models. As each regressor was added, the new equations fit was assessed using the coefficient of determination (R2 ) and the sum of squared error (SSE). If there was a discrepancy as to whether an added regressor significantly contributed to the fit of the equation, a hypothesis test using the F-statistic was used to justify the regressors addition or removal. The models were then compared against the original data.<p> The models developed for the tine loading showed sufficient accuracy. The models for side loading of the bearing mounts and draft loading of the tool frame contained only one significant regressor. The lowest coefficient of correlation was R=0.63 for the model of side loading of the bearing mount. The statistical model for the vertical loading correlated well with the test data with a coefficient of correlation of R=0.95.

This thesis deals with the differences of various types of working tools of the Kverneland CLC Pro cultivator. Under specific conditions of the agricultural enterprise in the Czech Republic, it compares ordinary turning tine, carbide tine, Knock-on tine and renovated tine. In the introduction, there is a general overview of the properties of the soil, followed by an overview of various methods of soil cultivation, which are also related to various methods of founding plants. Furthermore, I summarized the types of cultivators and tillers, followed by an overview of the types of wear tines with their advantages and disadvantages. In the practical part of the work there is the monitoring of the lifetime of the compared technologies, the time required for their replacement, the cost of their acquisition and the overall economic evaluation.

The objectives of the study were to evaluate the soil disturbances and manure dispersion created by the AerWay aerator in a silt loam soil; and to generate a calibrated and validated soil-tool model using Discrete Element Methods (DEM) that simulate the draft and vertical forces of the aerator. The experimental results showed that a trend indicated that the faster tractor speeds would disturb more soil. After one hour with the manure application rate of 42 000 L/ha, manure was spread to a depth of 250 mm, 200 mm in the forward direction and 100 mm in the lateral direction. The model draft forces had a relative error of 13.4-31.2% when compared to the literature data between 100-150 mm depth while the predicted vertical force was found to linearly increase until 150 mm depth at around 700 N per rolling tine and plateaus until the full insertion of 200 mm.

The objectives of the study were to evaluate the soil disturbances and manure dispersion created by the AerWay aerator in a silt loam soil; and to generate a calibrated and validated soil-tool model using Discrete Element Methods (DEM) that simulate the draft and vertical forces of the aerator. The experimental results showed that a trend indicated that the faster tractor speeds would disturb more soil. After one hour with the manure application rate of 42 000 L/ha, manure was spread to a depth of 250 mm, 200 mm in the forward direction and 100 mm in the lateral direction. The model draft forces had a relative error of 13.4-31.2% when compared to the literature data between 100-150 mm depth while the predicted vertical force was found to linearly increase until 150 mm depth at around 700 N per rolling tine and plateaus until the full insertion of 200 mm.

No description available.

Comportement différé, anisotrope à la descenderie de Saint-Martin-la-Porte / Time-dependent, anisotropic behavior of Saint-Martin-la-Porte gallery

The agricultural industry is constantly evolving with automation as one of the current main focuses. This thesis involves the automation of a seedbed tine harrow, specifically the control of the tillage depth. The tillage depth is instrumental to farming as it determines the quality of the tilth, how well clods are broken up, and how well the soil aggregates are sorted. Poor control of the tillage depth could result in a bad harvest for the farmer. To control the tillage depth, several pulse radar sensors are installed on the harrow. The sensors measure the distance from the tines of the harrow to the ground. This distance is used in a control-loop that controls the hydraulic actuators that lifts and pushes down the frame of the harrow. Because of the rough working conditions of the tine harrow, the pulse radar sensors are in danger of being damaged or disturbed. A sensor not working as intended will lead to poor control of the tillage depth or even an unstable control system. The purpose of this thesis is to develop diagnosis systems to detect and generate an alarm if the output of a sensor is faulty. Four different systems are developed, three machine learning approaches and one model based approach. To be able to test and train models without having to go out on a field with a real harrow, a test rig is available. The test rig emulates a harrow driving on a field and the tests are designed to imitate plausible sensor errors. The models trained on and tuned to the test rig data are validated with data gathered from a real tine harrow.  The validation data from the harrow reveal that the main difference between the field data and test rig data are the vibrations and the sensor heights. The test rig produces negligible amounts of vibrations whereas the vibrations on a real harrow are immense. These differences affect the performances of the models and some tuning have to be done to the models to accommodate for the vibrations. The performance of the model based approach is good and no larger adjustments have to be made to it. The machine learning models created from the test rig data do not work in the field and new models are trained using field data. The new models are accurate and show great potential; albeit, it would be necessary to collect a lot more data for further training. Specifically, training the machine learning models on varying heights. In conclusion, the test rig data is similar to the field data but the vibrations in the system is missing and the heights differ. The missing vibrations results in that the models do not work as intended on field data. The conventional diagnostics approach works, but the generated alarms are binary meaning that the alarm only reveal if the signal is good or bad and does not provide any nuance. The machine learning models does provide nuance, meaning that the model can detect errors, what is causing the error, and warn if an error is about to occur. However, the machine learning models need a lot of data to train on to make this happen.

The diploma thesis is aimed at a comparison of tine and disc cultivators by several parameters which are most affecting the quality of a soil cultivation, and in the effect of the epigeic fauna, represented by ground beetles (Carabidae). Experiment was carried out twice during the season (after a harvest of wheat and rape) while soil was being cultivated with disc cultivator Lemken Rubin or tine cultivator Horsch Tiger. The experiment was carried out on the fields of ZD "Vysočina" Zbýšov and measured parameters were: plant residue decomposition, cultivation depth, diameter of aggregates, weed infestation and crop plant emergence, and abundance of ground beetles. Using the statistic tests, it was found, that almost every parameter describing the quality of the cultivation was influenced by the type of the cultivator. Tine cultivator had a higher decomposition of plant residues. This difference was more obvious when cultivating the field after rape harvest (P < 0.001) than field after wheat harvest (P < 0.01). Tine cultivator was more precise with keeping the cultivation depth as planned. Disc cultivator had a higher crumbling capacity. At the higher speed the machines were more inclining to come out of the ground at higher speeds (P < 0.05). A cultivation had a very negative influence on Carabidae population. On a rape stubble there was a 193 specimens caught in traps before the cultivation with two dominant species - Pseudoophonus rufipes and Pterostichus melanarius. Only 41 specimens was found in the traps after the cultivation.